Classic comedy explained for today

Marx Brothers
Four brothers find their identities through wildly exaggerated cultural appropriation. One is an unscrupulous Italian, One is an unruly and frenetic Mute pushing himself in everyone’s personal space, One is a wise-cracking Southern Gentleman of no means, and the other appears normal which is the joke. Sometimes there is singing. Sometimes musical solos with no explanation.
Why it is funny: Zeppo! His name is Zeppo!

Abbot and Costello
Two associates stick together no matter what. One is a well mannered gentleman who has a knowledge of strange ethnic names and generously tries to impart this knowledge to his associate, and is known for his patience, as the other man lacks the patience to follow along. That one is known for his catch phrase, “Hey, Abbot. Hey, Abbot.” 
Why this is funny: Today there are medications for this!

I Love Lucy
Lucy and Ricky are involved in a heteronormative BDSM relationship sometimes involving their neighbors Fred and Ethel. A complicated power dynamic is played out in the sample episode wherein the ladies buy new fancy hats, against the wishes of the men. Afterwards it goes according to the setup: each couple retires to their private domiciles and the women are spanked over the men’s knees as they wail. 
Why it is funny: Hats! Closets full of hats! Her name is Ethel! Separate twin beds!